BEIRUT – Syrian opposition media is reporting that airstrikes believed to be carried out by Russian warplanes have killed and wounded dozens of people in a northwestern Syrian market.

The Britain-based Syrian Observatory for Human Rights says Sunday's airstrikes struck the northwestern rebel-held town of Ariha. The Local Coordination Committees, an activist collective, says the airstrike struck a busy market, inflicting heavy casualties. Neither group provided a precise toll.

Opposition activists say scores of people have been killed by Russian strikes since the air campaign began on Sept. 30.

Russia says its airstrikes are targeting the Islamic State group and other "terrorists," but Western officials and Syrian rebels say most of the strikes have focused on central and northern Syria, where IS does not have a strong presence. .